Alex,
You may find it in the log files, but the fastest way to find out would be to setup a call and do a small packet capture from the CTMS cli as follows:
- utils network capture 1000 file size ALL
will capture 1000 packets in the filename you specify
- file get activelog platform/cli/
will allow you to copy that file to an sftp server and open the capture with for example wireshark
Hope that helps,
Johan